Movable electrode tube



April 20, 1948. w. c. MARSHALL I 2,439,942

MOVABLE ELEGTRODE TUBE Fiied Nov. 20, 1944 2 Sheets-Sheet 1 INVENTOR W/Y//am HIS ATTORNEY April 20, 194s. w.- c. MARSHALL 2,439,942

MOVABLE ELECTRODE TUBE Filed Nov. 20, 1944 2 Sheets-Sheet 2 Patented pr. 20, 1948 v:l-TED S TAT-ES PATENT Q FFI CE MGVABLE ELECTRODE TUBE (William-C. Marshall, Oakland, Calif. Application November 20, 1944, Serial No. .564,302

9,Claims. l

.My invention relates V:to electronic tubes; and the broad lobject of my .invention is the provision ofia tubefhaving a'fmovable electrode for varying the characteristics ofthe `output current, so .that such variation in current maybe `*used to evaluateon-fa dial .the degree of such movement; and if fdesired, :for -use .through suitable Vauxiliary devices `to cont-rol Athe operation of corrective, compensativemechanisms.

lAnother object 'is v'the provision of. a tube of thefcharacter `described in which movement of onef'o the electrodes andresulting variation .in anode A`voltage is automatically responsive to ehangefof position of- .the tube.

fone-'of :the fspecic objectives I of lmy invention istof-prov-ide means to serve viii-aircraft fas abasic reference `for accurate indication .and control of levelliight attitude.

:Another-1ob'ject :of the `.invention particularly applicable to aircraft, -is the fprovision of basic reference means including :an electronic tube which lis continuously-operative after .closing a control .-fswitch, and -which .immediately supplies azpositlvefand accurate indication of any pitching orfrolling movement of' the aircraft.

.'Still other objects include the provision of such fmeans having the l.important `olualities .of lowiiriitial: cost, low installation` and maintenance costs, flight lWeight with absence of heavy fhigh speed-rotary parts, and with increased simplicity, dependability rvand accuracy.

'Myzfinventionpossesses other objects and features off value, some of which'lwith the foregoing Will Ibefset forth in the following description of the invention. It is to be `understood-that:I do not limit myself to the -showingmade by thesaid `description .and the drawings vas `I may adopt variant forms ofthe invention within :the scope of the appended claims.

Re'terring tothe drawings: 1

"Figure `1-is -a 'frontor fbroadside elevation of a tubeembodyingfmy invention; and lliigure 2 isa sideifelevation thereof. In both views parts are Vshow-n in-section :Figure 3` is a cross -section on an enlarged scale 'throughithe three electrodes, the -planeof section being'indicated lley-the lines-#3 of Figure 1.

Figure 4 is `a detail Von an enlarged scaleof the grid iframe journal. The view is partly 'in verticalrsection, 4the plane of sectionA passing through .tl'rezaxis of .the bearing, as indicated by the line -etoffFigure 1.

Figure-,5 :is an elevation on an enlarged `.scale ofthe-grid `and gridsuppopting iframeiand coun- .terbalanceyand Figure 6,-isatop viewof thesame. 1

Egure 7 is a lwiring diagram showing one of my .tubes connected for operating an indicator dial; fand Figure 811s a wiring diagram .of the `oonnections ffor "two tubes in a system` for showing pitch and roll `of an V,aircraft .about its lateral and longitudinalzaxes respectively.

In terms of broad inclusion my invention comprises .an electronic tube 1enclosing a frame or chassis upon which are arrangedpreferably three baslcelectrodes,cathode, grid andfanode. ,'Ifwo of these, :preferably cathode and anode, `are vdisposed on ythe :chassis in a xed .archaving a com-mon center; andthe grid isA pivotallymounted for :moyementeabout .the `saine center so that :the arc -of coincidence, that-is, ,the degree of lapping of the -grid .over -the .cathode .and anode, varies with movement of the grid about its pivotal axis. Each :ofthe-electrodes extends preferably .through about .120:ofara and lov-:balancing the grid in sucha:positionthatwhen the :tubes long a-Xis -is vertical, the grid laps :the other two :electrodes ley-:6,02 then a vmere tipping-,of vthe ltube `to one side or the- Other :orzfrelative toits long axis, varies the arc l,of coincidencebetween lthe electrodes. lyfsupplyingia yfixed potential lto the cathode .and grid, :any'change 'inlthe :length .of .the arc of coincidence between these electrodes Land;y the anode resultsinafcorresponding changein anode current. Suchcurrentvariations are readily used to :operate :indicia evaluating lthe .change .or through relays to control other circuits.

ABecause 4mytube thus responds to atipping movement by 'varying :the 'electrical characteristics ofp-the anode output current, it becomes possible .to Aarrange. two such .tubes with .the grid axesxat right anglesto each other and yparallel respectively-:tothe horizontaland'lateral axes of ,anfairplana so that roll and pitch movements yof the plane rmay beinstantly indicated on a calibrated dial. Such apair of tubes may also be used 1through relays operated by anode current variationsztomanage circuits which lactuate fautomaticjiiight control means.

'I'husraapair/ofmy tubes provides abasicvreterencei-for thefaccurate indicationand yautomatic control of aircraft attitude with relation to level jight. 'Many other :application-s may be made of one or :more of my '.tubes. By mounting a singletube-.on a plvotedoatarm, the level of water'in a reservoir may be constantlyshown on 'a'dialcalibrated in feet yand located in a power house-miles faway. By mounting a tube lon a pivotedfiarm extending into allowing stream, the velocityndvolume of @the flow may loe-evaluated, `or circuits =fmanaged for the .operation and control of mechanisms to be correlated to variations in such ilow.

In detail and referring iirst to Figure 1, my movable electrode tube comprises a iiattened but generally globular envelope 2, conveniently made of glass, and vacuumized in a manner well known in this art. For convenience in mounting and making connections, the envelope is provided with a stem 3 through which are sealed electrical conductors 4, 5, 6 and 1, connecting the prongs 3 on the lower end of the stem to their corresponding electrodes within the vacuumized envelope. The stem is surrounded by and embedded in the usual protective base cap 9.

For convenience in description the tube will be assumed to be arranged for operation in a vertical position as shown in Figure 1, with' its lorigitudinal vertical axis the stem and envelope. Extending upwardly from each side of the press I0 of the stem lis a glass arm II. The two arms form a yoke and at their upper ends merge symmetrically in'to Vopposite sides of the elongated glass ring I2, which lies in a horizontal plane perpendicular to the vertical axis of the envelope. Within and upon this glass frame or chassis, the operating partslof my device are mounted. l

The preferred embodiment of my invention here selected for explanation includes three elec-Y trodes, cathode, anode and grid, of which one,

preferably the grid is mounted for movement relative to the other two. Fixed on opposite sides of the 'chassis ring are pivot bearings, each formed by a sapphire bearing block I 3 carried'on the end of a threaded plug I4, adjustable in a threaded sleeve IG, moulded into the body of the ring I2. Y

Journaled in the pivot bearings is a shaft I1 having at its center a square hub yon which the grid supporting frame I8 is fxedly held by a 'col-v lar I9 pressed on the reduced end of the shaft. The grid supporting frame bifurcates at one end into the arms Ida and Ib, to the ends of which a split tubular grid 2| is xed. Preferably the grid is made of a nickel wire mesh; and extends over an arc of about 120 centered in the axis of the Vgrid supporting frame pivot bearings. Preferably the grid'has a C-shape section when viewed in a radial plane' (Figure 3), the split or gap 22 being on the sideopposite to the pivotal axis of the grid frame.

Means are provided for balancing the grid and its supporting frame in a position in which it is symmetrical with respect to a horizontal plane through the pivotal axis'of the grid. Fixed on the end of the frame (right hand end'Figure l) is a'counterbalancing vane 23 preferably integral with the grid supporting frame and formed with it from sheet aluminum. Thesize of the vane is 4calculated with reference to the dimen sions and weight of the grid and supporting frame to effect the balance referred'to but small adjustment is provided for by a smallcoil'24of -wire resiliently held on an arm stamped out of the body of the frame as best shown in Figures 5 and 6.

The vane 23 also has the function of damping sudden vibratory movements of the grid and frame, This is accomplished by mounting the vane between two permanent magnets '26 arranged with opposite poles adjacent, and xedly supported on the chassis by arms 21 embedded in the chassis yoke and ring. WithV operation of the device, the vane therefore moves across the magnetic eld, but minor oscillations are arrested passing centrally through 4 or damped by the eddy currents set up in the vane as it cuts across the ux. In an airplane, gyroscopic forces and also the influence of momentum and inertia tend to disturb the level position of the grid frame, and the stabilizing or damping of these movements is especially necessary in such use; although in some other applications of my tube such damping function may seldom if ever occur.

Means are provided for electrically connecting one of the leads 8 to the grid; and this is preferably done by welding or otherwise connecting to the inner terminal of conductor 5, the steel spring 3|, which extends upwardly in the tube to a fiat spiral coil 32, the end of which is iixed in a hole 33,'formed in the shaft I1. In addition to being the conductorwhich carries the grid current, this spring also contributes a stabilizing or smoothing effect on the movements of the grid during operation of the tube. Although its tortional stress on the grid shaft is extremely small, it tends to prevent too sudden or sensitive re` sponse to movement of the tube out'o'f the ver--` tical axis. It also tends to damp response to vibratory motion of the tube.` i

The anode 3S of my tube is also a splittubular structure, preferably but not necessarily, made of tantalum and xed to the post 31 in the horizontal ring and post 38 in the press, the latter being continuous with the conductor 6 sealed in the stem. As best shown in Figure 3, the shape of the anode 3S, like that of the grid 2l, is that of a C. Since the anode is xed in the chassis, which in operation of the tube may tip to one side or'the other, and sinceV the grid is balanced to remain in level position, the penetration of the curved tubular grid into the tubular anode will vary Widely. The anode is therefore curved in an arc having the same center as the arc of the grid; that is, the axis of the shaft I1. The gap or split 39 is placed on the inside to provide a freeway for the arms Ia and IBb of the'grid frame; and the parts are arranged as shown in Figure l, so that in normal level setting, the grid tube is centered in the anode tube radially; and circumferentially, about half of the grid tube extends into the anode tube, and the remainder of the grid tube extends above the upper end of the anode tube. In the positionv'of level setting then, the arc of coincidence is conveniently 60 with a range in operation from 0 to 120 of coincidence. It is obvious that by changing the length of the electrodes the are of coincidence at level setting could be increased up to with a range from 0 to 180. l

Connected to the conductors 4 and 1 in the stem, is the cathode 4I, preferably but not necessarily formed of a platinum or nickel alloy, and coated with an oxide of barium or strontium. The cathode enters the lower end of the tubular anode and extends upwardly therein and in the tubular grid, along the curved center line common to both, to emerge through the freeway in the grid provided by the gap therein, and at the upper end of the anode where it is secured to the post 42 set in the chassis ring. The post Vis connected by the conductor 43 disposed in'or on the chassis to the conductor 4 in the stem.

Figure '1 is a wiring diagram showing one of my tubes connected to indicate any deviation of its central longitudinal axis from the vertical. For simplicity in explanation, the' plane in which deviating movement occurs will be assumed to be vertical and perpendicular to the axis of the grid shaft. It will be assumed also that the tubelsso mounted on the structure 4with which it is to be used .that with the longitudinal axis of the t-ube in .fa vertical position, the igrid structure `,is ilevel, with about "one-half the grid lapping the anode 'and cathode. In Athis position :of the parts, vvthe carrying structure is inthe position of normal o peration, and the `current ow'fin 'the several :cn-- cuits when placed vin .operation are so adjusted that the indicator 45 .on .the dial .4'6 is atrzero.

If from fthis normal or level position, `the ltube is v-tipped to move its longitudinalaxis out .of the vertical position, the -grid and :grid supporting rra-me ftenfdtoremainin the rbalanced or level iposition, varyingthearc of .coincidence between the grid, and the cathode and anode which move together with the chasss,f.andfvarying in a proportionate ide'gree the anode output .'currenlt. This current can be accurately measured by a suitable metering device having the dial 46 calibrated in degrees each way from 0, which represents level position, so that tipping of the tube to the right message or left is reflected immediately in corresponding movement of the indicator 45. Quite obviously, the anode circuit may be also connected to a relay controlling a switch in the control circuit of mechanisms, the operation of which is related to the position of the tube and which are to be automatically managed by it; as for example, the moving of a valve in a penstock when a change in water level makes it desirable to vary the volume delivered to the wheels. Such relay controlled switches are well known and therefore need no detailed explanation here.

In Figure 8 is shown the wiring diagram and general arrangement by which two of my tubes may be utilized to give accurate dial indications of the pitch and roll of an airplane during ight. For simplicity, separate dials are shown, but it will be understood that indicating devices for both tubes may be arranged on one dial, so that both pitch and roll are shown by one instrument. (In this use of my tubes, one of them is disposed with the grid frame pivotal axis on or parallel to the longitudinal axis of the airplane; and the other tube is disposed with the pivotal axis at right angles to such longitudinal axis. In each, the pivotal axis must lie in a horizontal plane when the airplane is in the position of level flight.

With the plane in the position it will assume in level ight, the tubes are placed and the circuits adjusted to give a zero reading on each dia1 5| and 52. With the start of 4a flight, the mere closing of the switch 53 puts the system in operation. The rst tube 54 is sensitive to any turning of the plane about its longitudinal axis, that is, to roll; and variati-on in the arc of coincidence between the electrodes of that tube is immediately evaluated on the dial 5| in degrees of rolling movement. The second tube 56 is sensitive to turning of the plane about its lateral axis, that is, to pitch; and variation in the arc of coincidence between the electrode of the second tube is instantly evaluated in degrees on the dial 52. As in the single tube, relay-operated switches in control circuits may be utilized to provide automatically operating means of known character for the control of ight.

I claim:

1. An electron discharge device comprising a chassis, a grid frame pivoted in the chassis, a grid mounted on the grid frame in an arc centered at the axis of the grid frame pivot, and an anode and a cathode supported on the lchassis and lying at the side .of the grid in arcs centered at the axis of the grid frame pivot.

2. feleotrondischarge .device comprising la chassis, "a igrid'and supporting :trame therefor :pivotally ibalamcedfcn the chassis'feand'moimting the .grid iornnovement ,in :an varc':centered Vat Y.the pivotal .axis Arif fthe igiddyand :an anode -anda cathode `supported :oni-the :chassis `and .flying adjacent the -gridrin :arcs @centered @at the yaxis of the'igrid pivot.

3. electron :discharge device comprising a chassis, a grid frame pivoted in the chassis, a grid mountedon the grid -rarne'in'an arc centered at the axis-of the grid framepivot,counterbalancing means on the grid frame, and yananode and a cathode supported on the chassis and lying at the side oi the grid in arcs Ycentered'ait'. the axis ci thefgrtd frame pivot.

4. An .electron discharge fdevice comprising a chassis, a grid and supporting frame therefor including a, counterbalancing vane and pivotally balanced on the chassis and mounting the grid for movement in an arc centered at the pivotal axis of the grid, an anode and a cathode supported on the chassis and lying adjacent the grid in arcs centered at the axis of the grid pivot, and magnetic means iixed on the chassis on each side of the vane for damping vibratory movements in the grid supporting frame.

`5. An electron discharge device comprising a chassis, a, grid and supporting frame therefor pivotally balanced on the chassis and mounting the grid for movement in an arc centered at the pivotal axis of the grid, an anode and a cathode supported on the chassis and lying adjacent the grid in arcs centered at the axis of the grid pivot, and means mounted on the `chassis for causing a magnetic flux adjacent a part of the grid supporting frame.

6. An electron discharge device comprising a chassis, a grid and supporting frame therefor pivotally balanced on the chassis and mounting the grid for movement in an arc centered at the pivotal axis of the grid, an anode and a cathode supported on the chassis and lying adjacent the grid in arcs centered at the axis of the grid pivot, and a magnet mounted on the chassis adjacent a portion of the grid supporting frame.

'7. An electron discharge device comprising a chassis, a grid and supporting frame therefor pivotally balanced on the chassis and mounting the grid for movement in an arc centered at the pivotal axis of the grid, an anode and a cathode supported on the chassis and lying adjacent the grid in arcs centered at the axis of the grid pivot, an envelope surrounding the chassis, and electric conductors connecting the grid, cathode and anode to individual terminals therefor.

8. An electron discharge device comprising a chassis, a grid and supporting frame therefor including a counterbalancing vane and pivotally balanced on the chassis and mounting the grid for movement in an arc centered at the pivotal axis of the grid, an anode and a cathode supported on the chassis and lying adjacent the grid in arcs centered at the axis of the grid pivot, a magnet xed on the chassis adjacent the grid frame vane, an envelope enclosing the device, external leads on said envelope, and means electrically connecting said leads to the grid and anode and cathode.

9. An electron discharge device comprising a chassis, a grid and supporting frame therefor including a counterbalancing vane and pivotally balanced on the chassis and mounting the grid for movement in an arc centered at the pivotal axis of the grid, an anode and a cathode supported on the chassis and lying adjacent the grid in arcs 7 centered at the axis of the grid pivot,V a. magnet xed on the chassis adjacent the grid frame vane, an envelope enclosing the device, external leads on said envelope, and means electrically connecting said leads to the grid and anode and cathode, said last named means connected to the grid being a spring for resisting in slight degree relative movement of the grid about its pivot.

WILLIAM C. MARSHALL.

REFERENCES CITED The following references are of recordvin the le of this patent:

UN'I'I'ED4 STATES PATENTS Name Date DeForest July 15, 1919 Number Number 15 Number France July 3, 1939 

